[llvm] [InstCombine] Fold `mul (sext bool X), Y` into `select X, -Y, 0` (PR #84792)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> Codegen looks a bit worse

mul typically takes ~3 cycles. Do you mean we should revert the transform to reduce code size?


https://github.com/llvm/llvm-project/pull/84792